This invention generally relates to devices for entering data into a data processing system and more specifically to a data entry device that uses a keyboard for entering textual materials into a text-editing system.
Keyboard data entry devices, such as teletypewriters, constitute one of several classes of data entry devices for data processing systems. They are used by both sophisticated and non-sophisticated users of data processing system in a wide variety of data processing applications. Their acceptance is due, in large part, to the basic similarity between their keyboards and conventional typewriter keyboards. The keyboards in these data entry devices differ from conventional typewriter keyboards mainly by the addition of a few control keys that are necessary for the data entry device to function properly in a data processing environment.
In certain applications, however, keyboard data entry devices have limitations. Like a conventional typewriter, each keyboard usually is limited to a predetermined set of symbols or characters. Normally, the set of symbols corresponds to a particular language (e.g., English, French or German). It is therefore difficult to utilize a keyboard data entry device constructed for entering data in one language (e.g., English) for entering data in another language (e.g., French). One such application is text-editing, in which a text-editing system operates under the control of a data processor. These systems are gaining increasing acceptance for use in the publication of various books and periodicals. While initially these systems operated in a single language, publishers and other users of text editing systems are finding it very desirable to have a capability of editing text in one or more diverse languages simultaneously. Based upon the state of the existing art, we see three obvious approaches that can be taken to provide this capability.
In one such approach, a text editing system includes a number of separate data entry devices, and each device is structured for only a single language or group of related languages that are within the capability of the text editing system. In operation, an operator strikes a data input key. A matrix encoder in the device then generates a key code which is transferred to a data processor. The data processor "knows" the language for the data entry device and converts the key code into an appropriate character code for display and text editing purposes.
Although this represents a straight-forward technical approach, systems utilizing data entry devices of this type can become expensive if they have the capability to operate with a wide variety of languages. Specifically, the number of data entry devices depends upon the number of different languages and the peak number of users for each language. For example, assume that a text editing system has the capability of editing English, French and German text. Also assume that there are 30 persons who will enter text and that ten persons enter text in each of the three languages. Moreover, assume that it desirable to allow the ten operators associated with one language to edit text simultaneously. Under these conditions, the system would have to include thirty data entry devices, even though the total number of operators entering text in all languages might never exceed 15. Under this example, the expense of the text editing system is increased by the direct costs of 15 additional terminals plus any added costs that might be necessary to support a system of that size.
A second potential approach involves the use of so-called "intelligent terminals". An intelligent terminal normally comprises an input keyboard, a visual display device and a terminal data processor. The terminal data processor enables the terminal to control its own display and to perform text editing functions. Typically, a number of intelligent terminals connect to a central data processor that interacts with the terminal processors only to change the information being stored at the terminals. In a text editing application involving multiple languages, an operator would designate a language and the central and terminal data processors would interact to transfer to the terminal the necessary information to support that language. If it were necessary to type a phrase in another language, the operator would have to stop and request a change in language, type the phrase and then request a change back to the original language.
The use of intelligent terminals in a multiple language environment also has other limitations. The system limits each terminal to processing materials in one language at any given time. Interaction between the central and terminal data processors for changing a language, even for a short insert, can unnecessarily burden the central data processor and detract from the overall operating efficiency of the text editing system. Moreover, intelligent terminals normally have standard keyboards, so it is difficult to denote any change in the meaning of any particular data input key or group of keys. Finally, the overall costs of such text editing systems can increase dramatically over the comparable costs of text editing systems that utilize a central data processor to perform all the text editing functions as described in the foregoing U.S. patents and patent applications.
The third possible approach is compatible with the text editing system described in the foregoing U.S. patents and patent applications. This approach minimizes the problems involved in the first two approaches, but it has its own limitations. A data entry device comprises a universal keyboard with the additional keys necessary to provide the various special characters encountered in diverse languages. For example, e and e keys would be added if French text were to be entered; and u and e keys, for German text. In one embodiment, these special characters could be entered by means of added keys positioned outside the area required by the standard typewriter keyboard for English. Alternatively, special control keys could be used in conjunction with the standard data input keys, so each data input key could provide a number of different characters. However, this approach can reduce the overall efficiency of entering textual materials. For example, if an operator were entering French text, he would have to perform a special procedure or strike a special key outside the normal keyboard area each time one of the specific characters (e.g., e, e and a) were encountered in the text. As operators entering such text normally are touch typists, this approach can detract from their overall efficiency. For example, extra keys outside the standard keyboard area usually would be located outside the normal reach of the typist. Likewise, the special sequence would be an unnatural sequence. Thus, in order to find such a key, it would be necessary for the touch typist to revert to a "hunt and peck" approach to data entry. As apparent, this is a slower and less accurate method for entering data because the operator's eyes must shift from the work to the keyboard and back.
Therefore, it is an object of this invention to provide an improved keyboard data entry device for a data processing system.
Another object of this invention is to provide a data entry device with an input keyboard that enables an operator to select symbols from predetermined sets of symbols.
Still another object of this invention is to provide a data entry device with an input keyboard that is relatively easy to use in a text editing environment.
Yet another object of this invention is to provide a data entry device with an input keyboard that enables an operator to enter text in several languages into a data processing system more efficiently.